Data on the extent, patterns and correlates of drug use among adolescents have been gathered through surveys of junior and senior high school students of a 12-city and town area. School enrollment lists at the beginning of the study period were utilized to identify random samples of students to be studied at three times separated by one-year intervals. Self-administered questionnaires were filled out anonymously. Students who dropped out of school after the study began have been identified and are being interviewed. The questionnaire contains questions concerning social-demographic and personal characteristics, drug-use behavior, motivations or barriers to drug usuage, attitudes toward drugs, and other correlates of drug using behaviors. Inteviews with drop-outs include, in addition, questions on attitude toward school and future plans, the family setting, and why the person dropped out. Data are also being gathered to described and categorize drug abuse prevention programs in the 37 schools in which students are being surveyed. These data will be used to evaluate the efficacy of the drug abuse prevention programs. They will compared to each other at single points in time, as well as over time. The over time comparisons will be examined for trends or changes which may be related to the conduct of the prevention programs. In addition, because the survey is comprehensive in scope, it is expected that the data will provide valid social-epidemiologic measures of adolescent drug use comparable to those being developed in other parts of the country.